Bed air bag deterrent system

ABSTRACT

A bed air bag deterrent apparatus for deterring a bed occupant from getting out of bed without assistance of a caregiver, including a deterrent device mounted on a bed frame and activated by a detection system to deter or delay the bed occupant from getting out of bed, a detection system having a detector for detecting when the bed occupant is attempting to get out of bed, and a control mechanism to for controlling the detection and deterrent systems. The deterrent device has an inflatable air bag mounted on the long side of a horizontally displaced rectangular support frame that is positioned on the horizontal surface of a bed frame. The detection system includes transmitters, sensors and pressure-sensitive bed occupancy pads for detecting the bed occupant. The control mechanism includes a bed occupancy monitor and audio system.

FIELD OF THE INVENTION

The present invention relates generally to safety equipment, and inparticular, to an inflatable air bag to deter a patient from getting outof bed and walking without the supervision or assistance of a caregiver.

BACKGROUND

It is well known that hospital patients such as the elderly or thosewith Alzheimer's disease are in danger when they attempt to walk or moveunaided from a bed. But an initial problem arises when they attempt toleave their bed as they are either physically too weak, or too confusedto negotiate a safe exit. As a result, upon their attempted exit, theymay misstep, fall out of the bed and injure themselves. Not only dothese falls sometimes result in serious injuries, but they may alsoresult in fatalities. Statistics show that falls in older persons andtheir resulting emotional effects, such as depression, are the leadingcause of unintentional death in people over 75 years of age.

Over the years, hospitals and nursing homes have used different forms ofimpediments to prevent patients from leaving their beds. Physicaldeterrents have been used to tie bed occupants to the bed. Thesedeterrents, however, are degrading, threatening, and have a tendency toagitate patients, particularly if they are confused about theirsurroundings. Also, railings have been used for many years. Recentstudies, however, have shown that not only do railings fail to preventfalls, but they may actually increase serious injuries to bed occupantswho attempt to climb over the railings to get out of the bed. Hospitaland nursing home patients should have some level of comfort, but priordeterring systems with these and other drawbacks have diminished thequality of life of patient hospitalization. Therefore, a need exists inhospitals, nursing homes and even hospice or home care arrangements, toprovide patients with a non-threatening deterrent.

U.S. Pat. No. 5,592,705, to West, discloses an impact cushioning devicethat rests on a floor to cushion a patient who has fallen off of a bed.However this device does not become effective until the patient isalready falling off of the bed so, it does not prevent the fall. Thesame is true of U.S. Pat. No. 5,052,065, also to West, that discloses acushion to protect wheelchair or bed occupants from fall-relatedinjuries. Since the cushion rests at a distance from its supportingstructure, the occupant has some distance to travel before the fall iscushioned.

When a cushion rests on the floor, it is possible that the bed orwheelchair occupant may bounce off the cushion and still land on thefloor. Also, the occupant may grab at the surroundings or nearby objectsin an attempt to prevent an impending fall (from either the bed orwheelchair) even though there is a cushion on the floor, resulting in amuscle strain. Thus, neither one of these devices prevents the fullrange of injuries that could occur should a patient either attempt tobreak their own fall or fall off of the cushion.

SUMMARY OF THE INVENTION

It is the primary object of the present invention to provide a new andimproved device to safeguard and deter patients who attempt to get outof their bed without the supervision or assistance of a caregiver. Thisdevice is particularly valuable for safeguarding patients in hospitalsand nursing homes or where patients are under a hospice care-likearrangement.

It is another object of the present invention to provide a detectionsystem to detect when an occupant is attempting to get out of bed.

It is another object of the present invention to provide a controlmechanism to carry a signal to an audio system and an inflation devicesuch as a fan for activating a deterrent device to deter or delay anoccupant from getting out of bed.

It is another object of the present invention to provide a method ofdetecting and deterring a bed occupant from getting out of bed.

The present invention is directed to an apparatus to deter a bedoccupant from getting out of a bed including a detection system, adeterrent device and a control mechanism. The detection system has athree-component detector for detecting when the bed occupant isattempting to get out of the bed. The deterrent device includes an airbag that is mounted on the frame of the bed that inflates to deter ordelay the bed occupant from getting out of bed in response to adetection system signal. The control mechanism controls the detectionsystem and deterrent device. The air bag is mounted on the long side ofthe bed and affixed to a support board or support frame on a bed frame.The air bag is inflated using a low-pressure inflation fan triggered bythe control mechanism. When deployed, the air bag is maintained in aproper position by external tethers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a bed with a deflated air bag of thepresent invention;

FIG. 2 is a perspective view of a bed with an inflated air bag of thepresent invention;

FIGS. 2A to 2C are perspective cross-sectional views of air bags of thepresent invention;

FIG. 3 is a perspective view of a bed with transmitters andreflectors/receivers of the present invention;

FIG. 4 is an end view of a bed with the sensor system of the presentinvention;

FIG. 5 is an end view of the bed with a side view of the inflated airbag of the present invention;

FIG. 6 is a top view of the bed with the inflated air bag of the presentinvention; and

FIG. 7 is a schematic of the inflation/deflation device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates a bed frame 10 including a horizontally disposedsupport platform 18 positioned between the bed frame 10 and a mattress 4and four support members or legs 20 integrally connected to the fourcorners of the support platform 18. Alternatively, a support frame 12and four support members or legs 20 integrally connected to the fourcorners of the frame 12 can be positioned between the bed frame 10 and amattress 4. The support platform 18 can be constructed from plywood,Masonite, a light metal or any other suitable and economical material.

The support frame 12 is substantially flat and can be of any shape, butpreferably is a rectangular-like frame of PVC pipe that substantiallycovers the bed frame 10. The support frame 12 is positioned on top ofthe bed frame 10. The mattress 4 rests upon the bed frame 10 inside thesupport frame 12, or on top of the support platform 18 depending onwhich is used.

Referring to FIG. 2, the air bag 2 inflates upwardly and along the longside of the bed 10. As illustrated, the inflated air bag 2 can becylindrical with a circular cross-section. However, the air bag 2 can beof any suitable cross-section such as, for example, rectangular,triangular and the like. See FIGS. 2A-2C. The bag should be long enoughto close or almost close the end of the bed with either no gap or a verysmall gap. The diameter of the bag should be the minimum required fordeterrence. The maximum size is preferably 2 feet in diameter. Thecritical feature of the air bag cross-section is that the size and shapeof the air bag are sufficient to deter or delay a bed occupant fromgetting out of the bed without assistance or supervision from thecaregiver. This is because the inflated air bag 2 deters or delays thebed occupant to provide a necessary amount of time for the caregiver toattend to the bed occupant attempting to get out of the bed or at leastkeep the occupant in the bed. The air bag in the preferred embodiment ismade from ripstop nylon, i.e., parachute cloth. However, an air bag madefrom any suitable air bag material can be used.

Although illustrated as having an air bag on one side only, two air bagscan be used, one on either side of the bed. As such, both bags mayactivate simultaneously or individually, depending on which side of thebed receives the signal of the bed occupants' attempted exit. However,when only one air bag 2 is used, a railing 6 can be used on the oppositeside of the bed. With the railing 6 on the opposite side, the bedoccupant will attempt to leave the bed via the open (i.e., deflated airbag) side. The deflated air bag 2 (FIGS. 1 and 4) is stored by asuitable retention device such as elastic bands on the side of the bed10 opposite the railing 6. Inside the air bag, a coil 60 of wire keepsthe bag material from entering and clogging the intake duct when thesame duct is used to deflate the bag. The air bag 2 is unobtrusive whennot being used (i.e., deflated). When not inflated, the air bag 2 doesnot interfere with the caregiver's duties around the bed or with aperson leaving the bed with the aid of a caregiver. Thus, the deflatedair bag 2 can be compactly stored next to the left, right or both sidesof the bed substantially along the long side of the bed.

Support panels 8, extend from the ends of the air bag and are attachedto the members or legs 20 on the opposite side of the bed from the bagand at the head and foot of the bed to close the gap between a headboard22 of the bed and the air bag 2 as well as the gap between the footboard24 of the bed and the air bag 2. See FIG. 6. The support panels alsoprevent the air bag from rotating down and away from the bed when theoccupant presses on the air bag while in the bed. The support panels 8are also ripstop nylon. The headboard 22 and footboard 24 can be of anyconvenient material such as plywood, Masonite or a light metal, andshould be detachable so that the bed air bag deterrent apparatus can bestored when not in use.

FIG. 3 illustrates the detection system to indicate when an occupant isattempting to leave the bed. The detection system is activated by aswitch (not shown) located near the bed, for example, on a nightstand.The detection system has three components: pressure-sensitive pads 30,at least one set of transmitters 32 a with sensors 34 a (reflectors orreceivers) above the bed, and at least one set of transmitters 32 b withsensors 34 b (reflectors or receivers) by the side of or below the bed.The sensors are positioned opposite a corresponding transmitter toreceive the signal from the transmitter therefore, each transmitter 32a, 32 b emits a signal to the corresponding sensor 34 a, 34 b. Thesignal from the transmitter can be a light signal, an infra-red signal,a sound signal, a radio signal or the like.

Pressure-sensitive pads 30 are positioned on the top surface of themattress 4, near the foot or head of the bed. The purpose of thepressure-sensitive pads 30 is to detect when a bed occupant attempts toget out of the bed. When the detection system switch is turned on, thepressure-sensitive pads 30 detect the weight of the bed occupant andremain stable. Removal of weight from the pressure-sensitive pads 30 isone of the conditions that signal to the control mechanism that theoccupant is attempting to get out of the bed. (The control mechanismwill be discussed in detail below). When additional conditions are met,the air bag 2 will inflate and an audible alarm will sound. Theadditional conditions exist when the transmitters 32 a, 32 b andreflectors/receivers 34 a, 34 b signals are interrupted.

The pressure sensitive pad in the preferred embodiment includes arectangular or other suitable shape air-tight bag, made of fabric or aplastic sheet, of suitable size to cover the foot of a patient's bed.The pad should be thin enough when inflated that its presence does notdisturb the patient. The preferred thickness of the pad is on the orderof an inch. Internal baffles of polyurethane foam or other suitablesubstance keep the thickness of the pad fixed when the airtight bag isfilled with air, rather than allowing the pad to become thicker as it isinflated. A nozzle at a corner of the pad or other suitable locationcommunicates with the inlet of a pressure sensitive switch via aflexible hose of suitable length.

The pressure sensitive switch closes an electrical contact when the airpressure at its inlet port rises above a pre-set and adjustable value. Asuitable switch is manufactured by Dwyer Corporation and has asensitivity range from 0.15 to 0.50 inches of water. When the patient'slegs are placed on the pad, the pressure inside rises. The hosecommunicates this increased pressure to the pressure sensitive switch,which closes its electrical contact. Closing the switch sends a signalto the detection device indicating that the patient's legs have beenplaced on the pad. When the patient's legs are removed from the pad, thepressure inside drops. This pressure drop is communicated to thepressure sensitive switch, the switch opens and another signal goes tothe control mechanism, indicating that the patient's legs are removedfrom the pad. In use, the pad is placed on the patient's bed under thebed linens. The preferred position of the pad is at the patient's feetnear its center in the patient's ordinary sleep position. Then when thefeet or legs of the patient are removed from the pad, as in the act ofgetting out of bed, the switch opens as described above and sends asignal to the detection device.

The pressure-sensitive pads 30 work in conjunction with the transmitters32 a, 32 b and reflectors/receivers 34 a, 34 b to form a detectionsystem. At least one set of transmitters 32 a is located side by sideand parallel to each other above the head of the bed and is directedtoward the foot of the bed. The transmitters emit signals that travel ina substantially horizontal direction relative to and above the bed. Inthe preferred embodiment the transmitters are positioned at the head ofthe bed and the reflectors/receivers are positioned at the foot of thebed; however, it is within the scope of this invention that thetransmitters and reflectors/receivers can be interchanged between theheadboard and the footboard. Each transmitted signal is received by aone or more reflector/receivers 34 a located above the foot of the bed,side by side and parallel to each other, facing the head of the bed andaligned with the corresponding transmitters 32 a to receive the signal.The transmitters 32 a and reflectors/receivers 34 a are mounted abovethe bed on the headboard 22 and footboard 24 of the bed.

In addition, a side transmitter 32 b generates signals by the side of orbelow the side of the bed. This transmitter 32 b is paired withcorresponding longitudinally spaced reflectors/receivers 34 b andlocated by the side of or below the side of the bed. This sidetransmitter 32 b and reflectors/receivers 34 b may be mounted on thevertical legs 20 of the bed frame 10. The side transmitter 32 b andreflectors/receivers 34 b capture the movement of the bed occupants'arms, legs or feet when they or other body parts of the patient hangover the edge of the bed 10 such as when the occupant attempts to getout of the bed. The side transmitter 32 b and reflector/receiver 34 bmay be affixed to both longitudinal sides of the bed in a planelaterally spaced from and parallel to the support platform 18 or belowthe platform 18.

In operation, when the detection system is turned on, signals are sentfrom the transmitters 32 a, 32 b to the reflectors/receivers 34 a, 34 b.When the sensor is a receiver, the transmitter 32 a, 32 b carries asignal and the receiver receives the signal and carries a correspondingsignal to the control mechanism indicating receipt of the signal fromthe transmitter. When the sensor is a reflector, the transmitters 32 a,32 b carry the signals and the reflectors 34 a, 34 b reflect the signalback to the transmitter, which carries a corresponding signal to thecontrol mechanism indicating receipt of the signal from the reflector.When the signals to the control mechanism are interrupted and theoccupant attempting to get out of bed removes weight from the pressuresensitive pads, the air bag will inflate.

FIG. 4 illustrates the control mechanism. The control mechanism isattached to the detection system and includes low voltage lines 40 thatcarry signals to a bed occupancy monitor 42. The bed occupancy monitor,such as the INFORMER manufactured by Micro-Tech Medical, Inc., of WestHartford, Conn., indicates by an alarm or signal when an occupant isattempting to leave the bed. The bed occupancy monitor 42 of the controlmechanism receives the signals from the detection system and, in turn,carries a signal to operate an audio system 46 for example, a taperecorder. The audio system 46 produces a recorded voice messagesimultaneously with the inflating of the air bag that will urge the bedoccupant to remain in bed.

Referring to FIGS. 4, 5 and 7, the air bag 2 is inflated by an inflationdevice, such as an inflation fan 48 connected through a normally openedvalve 52, a manifold 54, and by a flexible duct 50 to the air bag inlet.The inflation fan 48 is activated so that it quickly blows air into thedeflated air bag 2 upon a signal from a detection system that theoccupant is leaving the bed. The detection system will be discussed inmore detail below. The inflated air bag pressure should not exceed ½psig.

A deflation device in FIG. 7, removes air from the air bag after use.The deflation device includes a normally closed valve 56 and a deflationfan 58. The deflation fan air flow exits the deflation fan opposite theduct 50 so as to draw air out of the air bag. The air bag deflationprocess is triggered when the audible alarm is canceled by the nurse orcaregiver pressing a stop-button (not shown) which may be on the bedoccupancy monitor. When the nurse or caregiver presses the stop-button,the normally opened valve 52 closes and the normally closed valve 56opens. The deflation device removes the air from the air bag through themanifold 54, the normally closed valve 56, and the deflation fan 58 toexit outside of the system. The manifold 54 and flexible duct 50 for thedeflation device are the same as those used for the inflation of the airbag. When the air bag is empty, or after a preset time, the deflationfan 58 will stop and both valves 52, 56 will resume their normalpositions. The normally closed valve will close and the normally openedvalve will re-open. The valves remain in these states of readiness toinflate the air bag when the detection device again detects an occupantattempting to get out of bed.

The inflation fan 48 is preferably located underneath the bed. The taperecorder, and bed occupancy monitor are located in a housing containingthe inflation/deflation device and electronics. The tape recorder andbed occupancy monitor are preferably in a separate package. Audiospeakers are separate from the control mechanism and are located nearthe bed for sound clarity.

In operation, when the occupant is in bed, and the power is turned on,the pressure-sensitive pads 30 and the transmitters 32 a, 32 b andreflectors/receivers 34 a, 34 b are activated. The activatedtransmitters 32 a, 32 b and reflectors/receivers 34 a, 34 b generateeither headboard to footboard or footboard to headboard signals. All ofthe signals from transmitters to receivers remain constant untilinterrupted by a body part of the bed occupant. The pads 30,transmitters 32 a, 32 b and reflectors/receivers 34 a, 34 b areconnected such that the bag will inflate and either an audible alarmwill sound, or the voice message will operate, or both when, at leasttwo out of the following three conditions exist at the same time: (1)one of the signals above the bed is interrupted; (2) there is nopressure on the pressure sensitive pads 30; (3) the signal on the sideof the bed is interrupted.

The first and second conditions are met when the person sits up in bed,thus interrupting at least one of the signals above the bed, and at thesame time moves his or her feet away from the end of the bed. Thisperson has not moved any part of their body off the bed but has sat upand pulled their feet toward their upper body in preparation to do so.The second and third conditions are met when the person moves both feetaway from the end of the bed and at the same time puts at least one legover the side of the bed, interrupting the side signal. This person islying on the bed with one leg over the side and the other away from theend of the bed, in preparation to put it over the side of the bed aswell. The first and third conditions are met when a person sits up inbed and at the same time puts one leg over the side. This person hasonly one leg over the side of the bed, the other being on the pressuresensitive pads, but is nonetheless preparing to leave the bed. Each ofthese sets of conditions will cause the audible alarm to sound and thebag to inflate.

The audible alarm will not sound and the voice message will not operatenor will the bag inflate when the occupant puts one leg over the sidebut retains the other on the pressure-sensitive pads; or when theoccupant raises both feet off of the pads, but lies flat in bed; or whenthe occupant sits up with legs remaining on the pressure sensitive pads.

The audible alarm can be mounted in any suitable position, for example,either on the bed headboard 22 or footboard 24, as well as immediatelyoutside of the patients' room or even at a nursing station. Further, thealarm can be a visual alarm used either alone or in conjunction with theaudible alarm. The detection system power switch can be mounted on thebed, nightstand, or on a wall near the bed.

The inflated air bag 2 is suspended above the floor and fixed in anupright position relative to the support frame 12 or the supportplatform 18 at the headboard 22 and footboard 24 by the support panels 8as well as tethers 16 made of heavy twine or the like. By being held tothe support frame 12 or the support platform 18 at the headboard 22, theair bag 2 remains suspended above the floor and blocks the path of thebed occupant attempting to get out of the bed. The tethers can be boltedor screwed to the support frame 12. Vertical support members 9 arelocated on the opposite side of the bed from the air bag and anchor thesupport panels 8. Sleeves 11 at the ends of the support panels 8 aredesigned to slip over vertical support members 9. See FIG. 6. Additionalsuspension of the air bag is accomplished by elastic bands. Elasticbands 14 extend from the support frame 12 at the headboard and footboardof the bed diagonally along the cross-section of the inflated air bag toa point approximately 45 degrees from the edge of the support frame. Theelastic bands 14 connect with the tethers 16 at points on the air bagfarthest from the support frame 12. The elastic bands can be bolted orscrewed to the support frame or vertical support 9.

The present invention may be embodied in other specific forms withoutdeparting from the spirit or essential characteristics thereof. Thepresently disclosed embodiments are therefore to be considered in allrespects as illustrative and not restrictive, the scope of the inventionbeing indicated by the appended claims, rather than the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are, therefore, to be embraced therein.

What is claimed is:
 1. A method of detecting and deterring bed occupantsfrom getting out of bed including a detection system havingtransmitters, receivers and pressure sensitive pads for detecting andsignaling bed occupant presence; a control mechanism to activate both anaudio system and an inflating deterrent for deterring the bed occupantfrom getting out of bed, comprising the steps of: detecting that a firstsignal from a transmitter above the bed is interrupted; andsimultaneously detecting that a second signal from a transmitter by aside of the bed is interrupted; applying a third signal to the audiosystem, located near the bed, when the first and second signals aredetected and operating the audio system in response to the third signal;producing a voice message, activated by the signal, urging the bedoccupant to remain in bed; triggering the inflation device to inflatethe deterrent; and inflating the deterrent.
 2. The method according toclaim 1, further comprising the step of sounding an audible alarm whenat least one signal from a transmitter above the bed is interrupted andwhen at least one signal from a transmitter by the side of the bed isinterrupted.
 3. The method according to claim 2, further comprising thestep of resetting the detection system and deterrent apparatus includingtriggering a deflation device to deflate the deterrent and canceling theaudible alarm.
 4. A method of detecting and deterring bed occupants fromgetting out of bed including a detection system having transmitters,receivers and pressure sensitive pads for detecting and signaling bedoccupant presence; a control mechanism to activate both an audio systemand an inflating deterrent for deterring the bed occupant from gettingout of bed, comprising the steps of: detecting that a first signal froma transmitter above the bed is interrupted; and simultaneously detectingan absence of pressure on the pressure sensitive pads; applying a secondsignal to the audio system, located near the bed, when the first signaland the absence of pressure are detected and operating the audio systemin response to the signal; producing a voice message, activated by thesignal, urging the bed occupant to remain in bed; triggering theinflation device to inflate the deterrent; and inflating the deterrent.5. The method according to claim 4, further comprising the step ofsounding an audible alarm when at least one signal from a transmitterabove the bed is interrupted and when there is no pressure on thepressure sensitive pads.
 6. The method according to claim 5, furthercomprising the step of resetting the detection system and deterrentapparatus including triggering a deflation device to deflate thedeterrent and cancel the audible alarm.
 7. A method of detecting anddeterring bed occupants from getting out of bed including a detectionsystem having transmitters, receivers and pressure sensitive pads fordetecting and signaling bed occupant presence; a control mechanism toactivate both an audio system and an inflating deterrent for deterringthe bed occupant from getting out of bed, comprising the steps of:detecting that a first signal from a transmitter by a side of the bed isinterrupted; detecting an absence of pressure on the pressure sensitivepads; and applying a second signal to the audio system, located near thebed, when the first signal and the absence of pressure are detected andoperating the audio system in response to the signal; producing a voicemessage, activated by the signal, urging the bed occupant to remain inbed; triggering the inflation device to inflate the deterrent; andinflating the deterrent.
 8. The method according to claim 7, furthercomprising the step of sounding an audible alarm when at least onesignal from a transmitter beside the bed is interrupted and when thereis no pressure on the pressure sensitive pads.
 9. The method accordingto claim 8, further comprising the step of resetting the detectionsystem and deterrent apparatus including triggering a deflation deviceto deflate the deterrent and cancel the audible alarm.